package java68_2;
import java.util.*;
public class ForTest2 {
    public static void main(String []args){
        Scanner in=new Scanner(System.in);
        System.out.println("input a number:");
        int k=in.nextInt();
        int i=2;
//        for(;i*i<=k;i++){
//            if(k%i==0)break;
//        }
        for(;i*i<=k&&k%i!=0;i++);

        if(i*i>k){
            System.out.println(k+"是质数");
        }else{
            System.out.println(k+"不是质数");
        }
    }
}
